In connection with Luer-Lock couplings previously used to lock together two components such as tubes, these Luer-Lock couplings are frequently made of relatively hard material, so that the screw treads used for such locking purposes will hold. By being able to effect this type of locking, it is possible to obtain a relatively good seal between coupling components therewith. In connection with Luer couplings which do not include such a locking mechanism, they are frequently made of a relatively flexible material in the female part, so as to ensure a satisfactory seal.
Because of this, it is often necessary to use different female parts for such Luer couplings with a locking mechanism, and for those without such a locking mechanism. It is most desirable, however, that it be made possible that the same female part can be used in connection with both types of couplings, while at the same time achieving satisfactory sealing and locking therewith.